Method of imaging amyloid deposits

ABSTRACT

The present invention provides a method of imaging amyloid deposits and radiolabeled compounds useful in imaging amyloid deposits. The invention also provides a method of delivering a therapeutic agent to amyloid deposits, a method of inhibiting the aggregation of amyloid proteins to form amyloid deposits, and a method of determining a compound&#39;s ability to inhibit aggregation of amyloid proteins.

This application claims the benefit of U.S. Provisional Application No.60/010,495 filed Jan. 24, 1996.

FIELD OF THE INVENTION

This invention relates to a method of imaging amyloid deposits and tolabeled compounds useful in imaging amyloid deposits. This inventionalso relates to a method of delivering a therapeutic agent to amyloiddeposits, a method of inhibiting the aggregation of amyloid proteins toform amyloid deposits, and a method of determining a compound's abilityto inhibit aggregation of amyloid proteins.

BACKGROUND OF THE INVENTION

Amyloidosis is a condition characterized by the accumulation of variousinsoluble, fibrillar proteins in the tissues of a patient. The fibrillarproteins that comprise the accumulations or deposits are called amyloidproteins. While the particular proteins or peptides found in thedeposits vary, the presence of fibrillar morphology and a large amountof β-sheet secondary structure is seen in many types of amyloids. Anamyloid deposit is formed by the aggregation of amyloid proteins,followed by the further combination of aggregates and/or amyloidproteins.

The presence of amyloid deposits has been shown in various diseases suchas Mediterranean fever, Muckle-Wells syndrome, idiopathetic myeloma,amyloid polyneuropathy, amyloid cardiomyopathy, systemic senileamyloidosis, amyloid polyneuropathy, hereditary cerebral hemorrhage withamyloidosis, Alzheimer's disease, Down's syndrome, Scrapie,Creutzfeldt-Jacob disease, Kuru, Gerstamnn-Straussler-Scheinkersyndrome, medullary carcinoma of the thyroid, Isolated atrial amyloid,β₂ -microglobulin amyloid in dialysis patients, inclusion body myositis,β₂ -amyloid deposits in muscle wasting disease, and Islets of Langerhansdiabetes Type II insulinoma.

Thus, a simple, noninvasive method for detecting and quantitatingamyloid deposits in a patient has been eagerly sought. Presently,detection of amyloid deposits involves histological analysis of biopsyor autopsy materials. Both methods have major drawbacks. For example, anautopsy can only be used for a postmortem diagnosis.

The direct imaging of amyloid deposits in vivo is difficult, as thedeposits have many of the same physical properties (i.e., density andwater content) as normal tissues. Attempts to image amyloid depositsusing magnetic resonance imaging (MRI) and computer-assisted tomography(CAT) have been disappointing and have detected amyloid deposits onlyunder certain favorable conditions. In addition, efforts to labelamyloid deposits with antibodies, serum amyloid P protein, or otherprobe molecules has provided some selectivity on the periphery oftissues, but has provided for poor imaging of tissue interiors.

Thus, it would be useful to have a noninvasive technique for imaging andquantitating amyloid deposits in a patient. In addition, it would beuseful to have compounds that inhibit the aggregation of amyloidproteins to form amyloid deposits and a method for determining acompound's ability to inhibit amyloid protein aggregation.

SUMMARY OF THE INVENTION

The present invention provides a method of imaging amyloid deposits, themethod comprising introducing into a patient a detectable quantity of alabeled compound having the Formula I or a pharmaceutically acceptablesalt, ester, amide, or prodrug thereof ##STR1## wherein X and Y are eachindependently C or N and the X═Y double bond has the transconfiguration;

Z is ##STR2## R¹ and R² are each independently hydrogen, C₁ -C₆ alkyl,C₁ -C₆ alkoxy, hydroxy, halogen, amino, di(C₁ -C₆ alkyl)amino, mono(C₁-C₆ alkyl)amino, nitro, C₁ -C₆ thioalkoxy, or R¹ and R² combined form abenzene, cyclopentane, or cyclohexane ring that is fused to the phenylring;

R³ is a lone pair of electrons, C₁ -C₁₀ alkyl, C₂ -C₁₀ alkenyl,arylalkyl, (heteroaryl)alkyl, (cycloalkyl)alkyl, arylalkenyl,diarylalkyl or --(CH₂)_(m) --A--(CH₂)_(n) --Q;

m is 1 to 6 and n is 0 to 6;

A is --O--, --S--, --NR⁴⁻, C═O, or a single bond;

Q is phenyl substituted with R⁷ or naphthyl substituted with R⁷ ;

R⁷ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, amino,di(C₁ -C₆ alkyl)amino, nitro, C₁ -C₆ thioalkoxy, aryl, heteroaryl,aryloxy, --CO-aryl, or arylthio;

R⁴ and R⁵ are each independently hydrogen, C₁ -C₆ alkyl or --NR⁴ R⁵represents a 5-, 6- or 7-membered ring containing nitrogen; and

R⁶ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, amino,di(C₁ -C₆ alkyl)amino, nitro, or C₁ -C₆ thioalkoxy; allowing sufficienttime for the labeled compound to become associated with amyloiddeposits; and detecting the labeled compound associated with the amyloiddeposits.

In a preferred embodiment of the compound having Formula I, X═Y is C═Cor N═N;

R¹ and R² are each independently hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy,halogen, nitro, C₁ -C₆ thioalkoxy, or R¹ and R² combined form a benzene,cyclopentane or cyclohexane ring that is fused to the phenyl ring;

R³ is C₁ -C₁₀ alkyl, C₂ -C₁₀ alkenyl, arylalkyl, (cycloalkyl)alkyl,arylalkenyl, diarylalkenyl, or --(CH₂)_(m) --A--(CH₂)_(n) --Q;

m is 1 to 5 and n is 0 to 4;

A is --O--, --S--, or a single bond;

Q is phenyl substituted with R⁷ or naphthyl substituted with R⁷ ;

R⁷ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, amino,di(C₁ -C₆ alkyl)amino, nitro, C₁ -C₆ thioalkoxy, aryl, aryloxy,--CO-aryl, or arylthio;

R⁴ and R⁵ are each independently hydrogen or C₁ -C₆ alkyl; and

R⁶ is hydrogen, C₁ -C₆ alkyl, or halogen.

In another preferred embodiment of the compound having Formula I, X═Y isC═C or N═N;

R¹ and R² are each independently hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy,halogen, nitro, or R¹ and R² combined form a (4,5), (5,6), or (6,7)benzene ring that is fused to the phenyl ring;

R³ is C₁ -C₁₀ alkyl, C₂ -C₁₀ alkenyl, arylalkyl, arylalkenyl,diarylalkyl, or --(CH₂)_(m) --A--(CH₂)_(n) --Q;

m is 2 to 4 and n is 0 to 3;

A is --O--, or a single bond;

Q is phenyl substituted with R⁷ or naphthyl substituted with R⁷ ;

R⁷ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, aryl,aryloxy, or --CO-aryl;

R⁴ and R⁵ are each independently hydrogen, methyl, ethyl, n-propyl orn-butyl; and

R⁶ is hydrogen or halogen.

In another aspect, the present invention provides a method of deliveringa therapeutic agent to an amyloid deposit comprising introducing into apatient a compound having the formula

    A--B--C

or a pharmaceutically acceptable salt, ester, amide, or prodrug thereof,wherein A is ##STR3## X and Y are each independently C or N and the X═Ydouble bond has the trans configuration;

Z is ##STR4## R¹ and R² are each independently hydrogen, C₁ -C₆ alkyl,C₁ -C₆ alkoxy, hydroxy, halogen, amino, di(C₁ -C₆ alkyl)amino, mono(C₁-C₆ alkyl)amino, nitro, C₁ -C₆ thioalkoxy or R¹ and R² combined form abenzene, cyclopentane, or cyclohexane ring that is fused to the phenylring;

R³ is a lone pair of electrons, C₁ -C₁₀ alkyl, C₂ -C₁₀ alkenyl,arylalkyl, (heteroaryl)alkyl, (cycloalkyl)alkyl, arylalkenyl,diarylalkyl or --(CH₂ )_(m) --A--(CH₂)_(n) --Q;

m is 1 to 6 and n is 0 to 6;

A is --O--, --S--, --NR⁴⁻, C═O, or a single bond;

Q is phenyl substituted with R⁷ or naphthyl substituted with R⁷ ;

R⁷ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, amino,di(C₁ -C₆ alkyl)amino, nitro, C₁ -C₆ thioalkoxy, aryl, heteroaryl,aryloxy, --CO-aryl or arylthio;

R⁴ and R⁵ are each independently hydrogen, C₁ -C₆ alkyl or --NR⁴ R⁵represents a 5-, 6-, or 7-membered ring containing nitrogen; and

R⁶ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, amino,di(C₁ -C₆ alkyl)amino, nitro or C₁ -C₆ thioalkoxy;

B is a linking moiety or a bond; and

C is a therapeutic agent.

The present invention also provides a method of inhibiting theaggregation of amyloid proteins to form amyloid deposits, the methodcomprising administering to a patient an amyloid protein aggregationinhibiting amount of a compound of Formula I or a pharmaceuticallyacceptable salt, ester, amide, or prodrug thereof ##STR5## wherein X andY are each independently C or N and the X═Y double bond has the transconfiguration;

Z is ##STR6## R¹ and R² are each independently hydrogen, C₁ -C₆ alkyl,C₁ -C₆ alkoxy, hydroxy, halogen, amino, di(C₁ -C₆ alkyl)amino, mono(C₁-C₆ alkyl)amino, nitro, C₁ -C₆ thioalkoxy or R¹ and R² combined form abenzene, cyclopentane, or cyclohexane ring that is fused to the phenylring;

R³ is a lone pair of electrons, C₁ -C₁₀ alkyl, C₂ -C₁₀ alkenyl,arylalkyl, (heteroaryl)alkyl, (cycloalkyl)alkyl, arylalkenyl,diarylalkyl, or --(CH₂)_(m) --A--(CH₂)_(n) --Q;

m is 1 to 6 and n is 0 to 6;

A is --O--, --S--, --NR⁴ , C═O, or a single bond;

Q is phenyl substituted with R⁷ or naphthyl substituted with R⁷ ;

R⁷ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, amino,di(C₁ -C₆ alkyl)amino, nitro, C₁ -C₆ thioalkoxy, aryl, heteroaryl,aryloxy, --CO-aryl, or arylthio;

R⁴ and R⁵ are each independently hydrogen, C₁ -C₆ alkyl or --NR⁴ R⁵represents a 5-, 6- or 7-membered ring containing nitrogen; and

R⁶ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, amino,di(C₁ -C₆ alkyl)amino, nitro, or C₁ -C₆ thioalkoxy.

The present invention also provides a method for determining acompound's ability to inhibit the aggregation of amyloid proteins, themethod comprising combining solutions of the compound with amyloidproteins under conditions that are known to lead to amyloid proteinaggregation; introducing into the solution a labeled compound of FormulaI or a pharmaceutically acceptable salt, ester, amide, or prodrugthereof ##STR7## wherein X and Y are each independently C or N and theX═Y double bond has the trans configuration;

Z is ##STR8## R¹ and R² are each independently hydrogen, C₁ -C₆ alkyl,C₁ -C₆ alkoxy, hydroxy, halogen, amino, di(C₁ -C₆ alkyl)amino, mono(C₁-C₆ alkyl)amino, nitro, C₁ -C₆ thioalkoxy, or R¹ and R² combined form abenzene, cyclopentane, or cyclohexane ring that is fused to the phenylring;

R³ is a lone pair of electrons, C₁ -C₁₀ alkyl, C₂ -C₁₀ alkenyl,arylalkyl, (heteroaryl)alkyl, (cycloalkyl)alkyl, arylalkenyl,diarylalkyl, or --(CH₂)_(m) --A--(CH₂)_(n) --Q;

m is 1 to 6 and n is 0 to 6;

A is --O--, --S--, --NR⁴⁻, C═O, or a single bond;

Q is phenyl substituted with R⁷ or naphthyl substituted with R⁷ ;

R⁷ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, amino,di(C₁ -C₆ alkyl)amino, nitro, C₁ -C₆ thioalkoxy, aryl, heteroaryl,aryloxy, --CO-aryl, or arylthio;

R⁴ and R5 are each independently hydrogen, C₁ -C₆ alkyl or --NR⁴ R⁵represents a 5-, 6- or 7-membered ring containing nitrogen; and

R⁶ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, amino,di(C₁ -C₆ alkyl)amino, nitro, or C₁ -C₆ thioalkoxy; filtering orcentrifuging the solution; and determining the amount of labeledcompound in the filtrate or supernatant.

Also provided is a compound of the Formula I or a pharmaceuticallyacceptable salt, ester, amide, or prodrug thereof ##STR9## wherein X andY are each independently C or N and the X═Y double bond has the transconfiguration;

Z is ##STR10## R¹ and R² are each independently hydrogen, C₁ -C₆ alkyl,C₁ -C₆ alkoxy, hydroxy, halogen, amino, di(C₁ -C₆ alkyl)amino, mono(C₁-C₆ alkyl)amino, nitro, C₁ -C₆ thioalkoxy, or R¹ and R² combined form abenzene, cyclopentane, or cyclohexane ring that is fused to the phenylring;

R³ is a lone pair of electrons, C₁ -C₁₀ alkyl, C₂ -C₁₀ alkenyl,arylalkyl, (heteroaryl)alkyl, (cycloalkyl)alkyl, arylalkenyl,diarylalkyl, or --(CH₂)_(m) --A--(CH₂)_(n) --Q;

m is 1 to 6 and n is 0 to 6;

A is --O--, --S--, --NR C═O, or a single bond;

Q is phenyl substituted with R⁷ or naphthyl substituted with R⁷ ;

R⁷ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, amino,di(C₁ -C₆ alkyl)amino, nitro, C₁ -C₆ thioalkoxy, aryl, heteroaryl,aryloxy, --CO-aryl, or arylthio;

R⁴ and R⁵ are each independently hydrogen, C₁ -C₆ alkyl or --NR⁴ R⁵represents a 5-, 6- or 7-membered ring containing nitrogen; and

R⁶ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, amino,di(C₁ -C₆ alkyl)amino, nitro, or C₁ -C₆ thioalkoxy,

and one or more atoms in the compound has been replaced with aradioisotope.

DETAILED DESCRIPTION OF THE INVENTION

This invention provides a method of imaging amyloid deposits thatcomprises introducing into a tissue or a patient a detectable quantityof a labeled compound of Formula I or a pharmaceutically acceptablesalt, ester, amide, or prodrug thereof ##STR11## wherein X and Y areeach independently C or N and the X═Y double bond has the transconfiguration;

Z is ##STR12## R¹ and R² are each independently hydrogen, C₁ -C₆ alkyl,C₁ -C₆ alkoxy, hydroxy, halogen, amino, mono(C₁ -C₆ alkyl)amino, di(C₁-C₆ alkyl)amino, nitro, C₁ -C₆ thioalkoxy, or R¹ and R² combined form abenzene, cyclopentane, or cyclohexane ring that is fused to the phenylring;

R³ is a lone pair of electrons, C₁ -C₁₀ alkyl, C₂ -C₁₀ alkenyl,arylalkyl, (heteroaryl)alkyl, (cycloalkyl)alkyl, arylalkenyl,diarylalkyl or --(CH₂)_(m) --A--(CH₂)_(n) --Q;

m is 1 to 6 and n is 0 to 6;

A is --O--, --S--, --NR⁴⁻, C═O, or a single bond;

Q is phenyl substituted with R⁷ or naphthyl substituted with R⁷ ;

R⁷ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, amino,di(C₁ -C₆ alkyl)amino, nitro, C₁ -C₆ thioalkoxy, aryl, heteroaryl,aryloxy, --CO-aryl, or arylthio;

R⁴ and R⁵ are each independently hydrogen, C₁ -C₆ alkyl or --NR⁴ R⁵represents a 5-, 6- or 7-membered ring containing nitrogen; and

R⁶ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, amino,di(C₁ -C₆ alkyl)amino, nitro, or C₁ -C₆ thioalkoxy;

allowing sufficient time for the labeled compound to become associatedwith amyloid deposits; and detecting the labeled compound associatedwith the amyloid deposits.

In a preferred embodiment of the invention,

X═Y is C═C or N═N;

R¹ and R² are each independently hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy,halogen, nitro, C₁ -C₆ thioalkoxy, or R¹ and R² combined form a benzene,cyclopentane or cyclohexane ring that is fused to the phenyl ring;

R³ is C₁ -C₁₀ alkyl, C₂ -C₁₀ alkenyl, arylalkyl, (cycloalkyl)alkyl,arylalkenyl, diarylalkenyl, or --(CH₂)_(m) --A--(CH₂)_(n) --Q;

m is 1 to 5 and n is 0 to 4;

A is --O--, --S--, or a single bond;

Q is phenyl substituted with R⁷ or naphthyl substituted with R⁷ ;

R⁷ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, amino,di(C₁ -C₆ alkyl)amino, nitro, C₁ -C₆ thioalkoxy, aryl, aryloxy,--CO-aryl, or arylthio;

R⁴ and R⁵ are each independently hydrogen or C₁ -C₆ alkyl; and

R⁶ is hydrogen, C₁ -C₆ alkyl, or halogen.

In a more preferred embodiment of the invention,

X═Y is C═C or N═N;

R¹ and R² are each independently hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy,halogen, nitro, or R¹ and R² combined form a (4,5), (5,6), or (6,7)benzene ring that is fused to the phenyl ring;

R is C₁ -C₁₀ alkyl, C₂ -C₁₀ alkenyl, arylalkyl, arylalkenyl,diarylalkyl, or --(CH₂)_(m) --A--(CH₂)_(n) --Q;

m is 2 to 4 and n is 0 to 3;

A is --O--, or a single bond;

Q is phenyl substituted with R⁷ or naphthyl substituted with R⁷ ;

R⁷ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, aryl,aryloxy, or --CO-aryl;

R⁴ and R⁵ are each independently hydrogen, methyl, ethyl, n-propyl orn-butyl; and

R⁶ is hydrogen or halogen.

In a most preferred embodiment of the invention, the labeled compound is

(E)-{4-[2-(5-Chlorobenzothiazol-2-yl)vinyl]phenyl}dimethylamine;

(E)-{4-[2-Benzothiazol-2-yl)vinyl])phenyl}dimethylamine;

(E)-Dimethyl-{4-[2-(5-methylbenzothiazol-2-yl)vinyl]phenyl}amine;

(E)-Dimethyl-{4-[2-(6-methylbenzothiazol-2-yl)vinyl]phenyl}amine;

(E)-{2-[2-(4-Dimethylaminophenyl)vinyl]benzothiazol-6-yl}dimethylamine;

(E)-3-Benzyl-2-[2-(4-dimethylaminophenyl)vinyl]benzothiazol-3-iumbromide;

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-ethylbenzothiazol-3-ium iodide;

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-1-methylnaphtho[1,2-d]thiazol-3-iumiodide;

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-methylbenzothiazol-3-iumiodide;

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-allylbenzothiazol-3-iumbromide;

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-butylbenzothiazol-3-ium iodide;

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-heptylbenzothiazol-3-iumiodide;

(E)-5-Chloro-2-[2-(4-dimethylaminophenyl)vinyl]-3-methylbenzothiazol-3-iumiodide;

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-5-fluoro-3-methylbenzothiazol-3-iumiodide;

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-benzyl-5-fluorobenzothiazol-3-iumbromide;

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3,5-dimethylbenzothiazol-3-iumiodide;

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3,6-dimethylbenzothiazol-3-iumiodide;

(E)-3-Benzyl-2-[2-(4-dimethylaminophenyl)vinyl]-6-methylbenzothiazol-3-iumbromide;

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-6-methoxy-3-methylbenzothiazol-3-iumiodide;

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-heptyl-6-methoxybenzothiazol-3-iumiodide;

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-methyl-6-nitrobenzothiazol-3-iumtoluene-4-sulfonate;

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-1-ethylnaphtho[1,2-d]thiazol-1-iumtoluene-4-sulfonate;

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-methylnaphtho[2,3-d]thiazol-3-iumiodide;

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-methylnaphtho[2,1-d]thiazol-3-iumiodide;

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(4-fluorobenzyl)benzothiazol-3-iumbromide;

(E)-3-Biphenyl-4-ylmethyl-2-[2-(4-dimethylaminophenyl)vinyl]benzothiazol-3-iumiodide;

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-naphthalen-2-ylmethylbenzothiazol-3-iumbromide;

(E)-3-Biphenyl-2-ylmethyl-2-[2-(4-dimethylaminophenyl)vinyl]benzothiazol-3-iumbromide;

(E)-3-(3-Benzoylbenzyl)-2-[2-(4-dimethylaminophenyl)vinyl]benzothiazol-3-iumbromide;

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(3-phenoxybenzyl)benzothiazol-3-iumbromide

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(3-phenylpropyl)benzothiazol-3-iumiodide;

(E,E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(3-phenylallyl)benzothiazol-3-iumbromide;

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(4,4-diphenylbutyl)benzothiazol-3-iumiodide;

(E)-3-(3-Benzyloxypropyl)-2-[2-(4-dimethylaminophenyl)vinyl]benzothiazol-3-iumiodide;

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(4-phenoxybutyl)benzothiazol-3-iumiodide;

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(5-phenylpentyl)benzothiazol-3-iumiodide;

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(5-phenoxypentyl)benzothiazol-3-iumiodide;

(E)-3-(2-Cyclohexylethyl)-2-[2-(4-dimethylaminophenyl)vinyl]benzothiazol-3-iumiodide;

(E)-2-[2-(4-Dimethylaminonaphthalen-1-yl)vinyl]-3-heptylbenzothiazol-3-iumiodide;

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(2-hydroxyethyl)benzothiazol-3-iumbromide;

(E)-2-[2-(4-Dimethylaminonaphthalen-1-yl)vinyl]-6-methoxy-3-methylbenzothiazol-3-iumiodide;

(E)-2-[2-(4-Dimethylaminonaphthalen-1-yl)vinyl]-1-methylnaphtho[1,2-d]thiazol-1-iumtoluene-4-sulfonate;

(E)-2-[2-(4-Diethylaminophenyl)vinyl]-3-methylbenzothiazol-3-iumchlordide;

(E)-2-[2-(4-Dibethylaminophenyl)vinyl]-3-heptylbenzothiazol-3-iumiodide;

(E)-2-[2-(4-Dibutylaminophenyl)vinyl]-3-heptylbenzothiazol-3-ium iodide;

(E)-3-Heptyl-2-[2-[(4-pyrrolidin-1-yl)phenyl]vinyl]benzothiazol-3-iumiodide;

[4-(Dimethylamino)phenylazo]benzothiazole;

4-(Benzothiazol-2-ylazo)naphthalen-1-ylamine;

2-[[4-(Dimethylamino)phenyl]azo]-6-methoxybenzothiazole;

6-Chloro-2-[[4-(dimethylamino)phenyl]azo]benzothiazole;

[4-(6-Methoxybenzothiazol-2-ylazo)naphthalen-1-yl]dimethylamine;

Dimethyl[4-(naphtho[1,2-d]thiazol-2-ylazo)naphthalen-1-yl]-amine;

2-[[(4-Dimethylamino)phenyl]azo]-6-methoxy-3-methylbenzothiazol-3-iummethylsulfate; and

2-[[(4-Dimethylamino)phenyl]azo]-3-methylbenzothiazolium methylsulfate.

It is recognized that many of the compounds above are salts. The free(nonsalt) compounds are also intended.

The term "alkyl" means a straight or branched chain hydrocarbon.Representative examples of alkyl groups are methyl, ethyl, propyl,isopropyl, isobutyl, butyl, tert-butyl, sec-butyl, pentyl, and hexyl.

The term "alkoxy" means an alkyl group attached to an oxygen atom.Representative examples of alkoxy groups include methoxy, ethoxy,tert-butoxy, propoxy, and isobutoxy.

The term "halogen" includes chlorine, fluorine, bromine, and iodine.

The term "di(alkyl)amine" means an amine group having two hydrogensreplaced by alkyl groups. Representative examples of di(alkyl)amines aredimethylamine, diethylamine, and methylethylamine.

The term "alkyenyl" means a branched or straight chain hydrocarboncontaining one or more carbon-carbon double bond.

The term "aryl" means an aromatic hydrocarbon. Representative examplesof aryl groups include phenyl and naphthyl.

The term "arylalkyl" means an alkyl group substituted with an arylgroup. Representative examples are benzyl and phenylethyl.

The term "heteroatom" includes oxygen, nitrogen, and sulfur.

The term "heteroaryl" means an aryl group wherein one or more carbonatom of the aromatic hydrocarbon has been replaced with a heteroatom.

The term "(heteroaryl)alkyl" means an alkyl group substituted with aheteroaryl group.

The term "cycloalkyl" means a cyclic hydrocarbon. Examples of cycloalkylgroups include cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.

The term "arylalkenyl" means an alkenyl group substituted with and arylgroup.

The term "diarylalkyl" means an alkyl group substituted with two arylgroups.

The term "aryloxy" means an aryl group attached to an oxygen atom.

The term "arylthio" means an aryl group attached to a sulfur atom.

The term "thioalkoxy" means an alkyl group attached to a sulfur atom.

The symbol "--" means a covalent bond.

The term "pharmaceutically acceptable salt, ester, amide, and prodrug"as used herein refers to those carboxylate salts, amino acid additionsalts, esters, amides, and prodrugs of the compounds of the presentinvention which are, within the scope of sound medical judgement,suitable for use in contact with the tissues of patients without unduetoxicity, irritation, allergic response, and the like, commensurate witha reasonable benefit/risk ratio, and effective for their intended use,as well as the zwitterionic forms, where possible, of the compounds ofthe invention. The term "salts" refers to the relatively nontoxic,inorganic and organic acid addition salts of compounds of the presentinvention. These salts can be prepared in situ during the finalisolation and purification of the compounds or by separately reactingthe purified compound in its free base form with a suitable organic orinorganic acid and isolating the salt thus formed. Representative saltsinclude the hydrobromide, hydrochloride, sulfate, bisulfate, nitrate,acetate, oxalate, valerate, oleate, palmitate, stearate, laurate,borate, benzoate, lactate, phosphate, tosylate, citrate, maleate,fumarate, succinate, tartrate, naphthylate mesylate, glucoheptonate,lactiobionate and laurylsulphonate salts, and the like. These mayinclude cations based on the alkali and alkaline earth metals, such assodium, lithium, potassium, calcium, magnesium, and the like, as wellas, nontoxic ammonium, quaternary ammonium and amine cations including,but not limited to ammonium, tetramethylammonium, tetraethylammonium,methylamine, dimethylamine, trimethylamine, triethylamine, ethylamine,and the like. (See, for example, Berge S. M., et al., PharmaceuticalSalts, J. Pharm. Sci., 66:1-19 (1977) which is incorporated herein byreference.)

Examples of pharmaceutically acceptable, nontoxic esters of thecompounds of this invention include C₁ -C₆ alkyl esters wherein thealkyl group is a straight or branched chain. Acceptable esters alsoinclude C₅ -C₇ cycloalkyl esters as well as arylalkyl esters such as,but not limited to benzyl. C₁ -C₄ alkyl esters are preferred. Esters ofthe compounds of the present invention may be prepared according toconventional methods.

Examples of pharmaceutically acceptable, nontoxic amides of thecompounds of this invention include amides derived from ammonia, primaryC₁ -C₆ alkyl amines and secondary C₁ -C₆ dialkyl amines wherein thealkyl groups are straight or branched chain. In the case of secondaryamines, the amine may also be in the form of a 5- or 6-memberedheterocycle containing one nitrogen atom. Amides derived from ammonia,C₁ -C₃ alkyl primary amides and C₁ -C₂ dialkyl secondary amides arepreferred. Amides of the compounds of the invention may be preparedaccording to conventional methods.

The term "prodrug" refers to compounds that are rapidly transformed invivo to yield the parent compound of the above formulas, for example, byhydrolysis in blood. A thorough discussion is provided in T. Higuchi andV. Stella, Pro-drugs as Novel Delivery Systems, Vol. 14 of the A.C.S.Symposium Series, and in Bioreversible Carriers in Drug Design, ed.Edward B. Roche, American Pharmaceutical Association and Pergamon Press,1987, both of which are incorporated herein by reference.

In addition, the compounds of the present invention can exist inunsolvated as well as solvated forms with pharmaceutically acceptablesolvents such as water, ethanol, and the like. In general, the solvatedforms are considered equivalent to the unsolvated forms for the purposesof the present invention.

The compounds of the present invention can exist in differentstereoisometric forms by virtue of the presence of asymmetric centers inthe compounds. It is contemplated that all stereoisometric forms of thecompounds, as well as mixture thereof, including racemic mixtures, formpart of this invention.

In the first step of the present method of imaging, a labeled compoundof Formula I is introduced into a tissue or a patient in a detectablequantity. The compound is typically part of a pharmaceutical compositionand is administered to the tissue or the patient by methods well knownto those skilled in the art.

For example, the compound can be administered either orally, rectally,parenterally (intravenous, by intramuscularly or subcutaneously),intracisternally, intravaginally, intraperitoneally, intravesically,locally (powders, ointments or drops), or as a buccal or nasal spray.

Compositions suitable for parenteral injection may comprisephysiologically acceptable sterile aqueous or nonaqueous solutions,dispersions, suspensions or emulsions, and sterile powders forreconstitution into sterile injectable solutions or dispersions.Examples of suitable aqueous and nonaqueous carriers, diluents,solvents, or vehicles include water, ethanol, polyols (propyleneglycol,polyethyleneglycol, glycerol, and the like), suitable mixtures thereof,vegetable oils (such as olive oil), and injectable organic esters suchas ethyl oleate. Proper fluidity can be maintained, for example, by theuse of a coating such as lecithin, by the maintenance of the requiredparticle size in the case of dispersions and by the use of surfactants.

These compositions may also contain adjuvants such as preserving,wetting, emulsifying, and dispensing agents. Prevention of the action ofmicroorganisms can be ensured by various antibacterial and antifungalagents, for example, parabens, chlorobutanol, phenol, sorbic acid, andthe like. It may also be desirable to include isotonic agents, forexample sugars, sodium chloride, and the like. Prolonged absorption ofthe injectable pharmaceutical form can be brought about by the use ofagents delaying absorption, for example, aluminum monostearate andgelatin.

Solid dosage forms for oral administration include capsules, tablets,pills, powders, and granules. In such solid dosage forms, the activecompound is admixed with at least one inert customary excipient (orcarrier) such as sodium citrate or dicalcium phosphate or (a) fillers orextenders, as for example, starches, lactose, sucrose, glucose,mannitol, and silicic acid; (b) binders, as for example,carboxymethylcellulose, alignates, gelatin, polyvinylpyrrolidone,sucrose, and acacia; (c) humectants, as for example, glycerol; (d)disintegrating agents, as for example, agar-agar, calcium carbonate,potato or tapioca starch, alginic acid, certain complex silicates andsodium carbonate; (e) solution retarders, as for example paraffin; (f)absorption accelerators, as for example, quaternary ammonium compounds;(g) wetting agents, as for example, cetyl alcohol and glycerolmonostearate; (h) adsorbents, as for example, kaolin and bentonite; and(i) lubricants, as for example, talc, calcium stearate, magnesiumstearate, solid polyethylene glycols, sodium lauryl sulfate, or mixturesthereof. In the case of capsules, tablets, and pills, the dosage formsmay also comprise buffering agents.

Solid compositions of a similar type may also be employed as fillers insoft- and hard-filled gelatin capsules using such excipients as lactoseor milk sugar, as well as high molecular weight polyethyleneglycols, andthe like.

Solid dosage forms such as tablets, dragees, capsules, pills, andgranules can be prepared with coatings and shells, such as entericcoatings and others well known in the art. They may contain opacifyingagents, and can also be of such composition that they release the activecompound or compounds in a certain part of the intestinal tract in adelayed manner. Examples of embedding compositions which can be used arepolymeric substances and waxes. The active compounds can also be inmicroencapsulated form, if appropriate, with one or more of theabove-mentioned excipients.

Liquid dosage forms for oral administration include pharmaceuticallyacceptable emulsions, solutions, suspensions, syrups, and elixirs. Inaddition to the active compounds, the liquid dosage forms may containinert diluents commonly used in the art, such as water or othersolvents, solubilizing agents and emulsifiers, as for example, ethylalcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzylalcohol, benzyl benzoate, propyleneglycol, 1,3-butyleneglycol,dimethylformamide, oils, in particular, cottonseed oil, groundnut oil,corn germ oil, olive oil, castor oil, and sesame oil, glycerol,tetrahydrofurfuryl alcohol, polyethyleneglycols, and fatty acid estersof sorbitan or mixtures of these substances, and the like.

Besides such inert diluents, the composition can also include adjuvants,such as wetting agents, emulsifying and suspending agents, sweetening,flavoring, and perfuming agents.

Suspensions, in addition to the active compounds, may contain suspendingagents, as for example, ethoxylated isostearyl alcohols, polyoxyethylenesorbitol and sorbitan esters, microcrystalline cellulose, aluminummetahydroxide, bentonite, agar-agar and tragacanth, or mixtures of thesesubstances, and the like.

Compositions for rectal administrations are preferably suppositorieswhich can be prepared by mixing the compounds of the present inventionwith suitable nonirritating excipients or carriers such as cocoa butter,polyethyleneglycol or a suppository wax, which are solid at ordinarytemperatures but liquid at body temperature and therefore, melt in therectum or vaginal cavity and release the active component.

Dosage forms for topical administration of a compound of this inventioninclude ointments, powders, sprays, and inhalants. The active componentis admixed under sterile conditions with a physiologically acceptablecarrier and any preservatives, buffers or propellants as may berequired. Ophthalmic formulations, eye ointments, powders, and solutionsare also contemplated as being within the scope of this invention.

In a preferred embodiment of the invention, the labeled compound isintroduced into a patient in a detectable quantity and after sufficienttime has passed for the compound to become associated with amyloiddeposits, the labeled compound is detected noninvasively inside thepatient. In another embodiment of the invention, a labeled compound ofFormula I is introduced into a patient, sufficient time is allowed forthe compound to become associated with amyloid deposits, and then asample of tissue from the patient is removed and the labeled compound inthe tissue is detected apart from the patient. In a third embodiment ofthe invention, a tissue sample is removed from a patient and a labeledcompound of Formula I is introduced into the tissue sample. After asufficient amount of time for the compound to become bound to amyloiddeposits, the compound is detected.

The administration of the labeled compound to a patient can be by ageneral or local administration route. For example, the labeled compoundmay be administered to the patient such that it is delivered throughoutthe body. Alternatively, the labeled compound can be administered to aspecific organ or tissue of interest. For example, it is desirable tolocate and quantitate amyloid deposits in the brain in order to diagnoseor track the progress of Alzheimer's disease in a patient.

The term "tissue" means a part of a patient's body. Examples of tissuesinclude the brain, heart, liver, blood vessels, and arteries. Adetectable quantity is a quantity of labeled compound necessary to bedetected by the detection method chosen. The amount of a labeledcompound to be introduced into a patient in order to provide fordetection can readily be determined by those skilled in the art. Forexample, increasing amounts of the labeled compound can be given to apatient until the compound is detected by the detection method ofchoice. A label is introduced into the compounds to provide fordetection of the compounds.

The term "patient" means humans and other animals. Those skilled in theart are also familiar with determining the amount of time sufficient fora compound to become associated with amyloid deposits. The amount oftime necessary can easily be determined by introducing a detectableamount of a labeled compound of Formula I into a patient and thendetecting the labeled compound at various times after administration.

The term "associated" means a chemical interaction between the labeledcompound and the amyloid deposit. Examples of associations includecovalent bonds, ionic bonds, hydrophilic-hydrophilic interactions,hydrophobic-hydrophobic interactions, and complexes.

Those skilled in the art are familiar with the various ways to detectlabeled compounds. For example, magnetic resonance imaging (MRI),positron emission tomography (PET), or single photon emission computedtomography (SPECT) can be used to detect radiolabeled compounds. Thelabel that is introduced into the compound will depend on the detectionmethod desired. For example, if PET is selected as a detection method,the compound must possess a positron-emitting atom, such as ¹¹ C or ⁸ F.

Another example of a suitable label in a compound of Formula I is anatom such as ¹³ C, ¹⁵ N, or ¹⁹ F which can be detected using magneticresonance imaging (MRI) which is also sometimes called nuclear magneticresonance (NMR). In addition, the labeled compounds of Formula I mayalso be detected by MRI using paramagnetic contrast agents.

Another example of detection is electron paramagnetic resonance (EPR).In this case, EPR probes which are well-known in the art, such asnitroxides, can be used.

The imaging of amyloid deposits can also be carried out quantitativelyso that the amount of amyloid deposits can be determined.

The present invention also provides a method of delivering a therapeuticagent to an amyloid deposit comprising introducing into a patient acompound having the formula

    A--B--C

or a pharmaceutically acceptable salt, ester, amide or prodrug thereof,wherein A is ##STR13## X and Y are each independently C or N and the X═Ydouble bond has the trans configuration;

Z is ##STR14## R¹ and R² are each independently hydrogen, C₁ -C₆ alkyl,C₁ -C₆ alkoxy, hydroxy, halogen, amino, di(C₁ -C₆ alkyl)amino, nitro, C₁-C₆ thioalkoxy or R¹ and R² combined form a benzene, cyclopentane, orcyclohexane ring that is fused to the phenyl ring;

R³ is a lone pair of electrons, C₁ -C₁₀ alkyl, C₂ -C₁₀ alkenyl,arylalkyl, (heteroaryl)alkyl, (cycloalkyl)alkyl, arylalkenyl,diarylalkyl or --(CH₂)_(m) --A--(CH₂)_(n) --Q;

m is 1 to 6 and n is 0 to 6;

A is --O--, --S--, --NR⁴⁻, C═O, or a single bond;

Q is phenyl substituted with R⁷ or naphthyl substituted with R⁷ ;

R⁷ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, amino,di(C₁ -C₆ alkyl)amino, nitro, C₁ -C₆ thioalkoxy, aryl, heteroaryl,aryloxy, --CO-aryl or arylthio;

R⁴ and R⁵ are each independently hydrogen, C₁ -C₆ alkyl or --NR⁴ R⁵represents a 5-, 6-, or 7-membered ring containing nitrogen; and

R⁶ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, amino,di(C₁ -C₆ alkyl)amino, nitro, or C₁ -C₆ thioalkoxy;

B is a linking moiety or a bond; and

C is a therapeutic agent.

The linking moiety B can be any linking moiety known to those skilled inthe art. The linking moiety is used to attach the therapeutic agent C toa Compound A that binds to amyloids deposits. Examples of suitablelinking moieties include, but are not limited to, covalent bonds, aminoacids, peptides or proteins, alkyl chains, hydroxyacids, and diacids.

The therapeutic agent C can be any therapeutic agent known to thoseskilled in the art. In particular, the therapeutic agent is one that isintended for delivery to amyloid deposits or to the organs containingamyloid deposits. For example, the therapeutic agent can block orinhibit the growth or toxicity of amyloid deposits. The therapeuticagents can also aid in the degradation of amyloid deposits such asthrough proteolytic degradation. Examples of suitable therapeutic agentsinclude, but are not limited to, nonsteroidal anti-inflammatorycompounds (NSAIDS) such as ibuprofen or indomethacin, or compounds thataffect the rate of production of the amyloid proteins.

The present invention also provides a method of inhibiting theaggregation of amyloid proteins to form amyloid deposits, byadministering to a patient an amyloid inhibiting amount of a compound ofFormula I. Those skilled in the art are readily able to determine anamyloid inhibiting amount by simply administering a compound of FormulaI to a patient in increasing amounts until the growth of amyloiddeposits is decreased or stopped. The rate of growth can be assessedusing imaging as described above or by taking a tissue sample from apatient and observing the amyloid deposits therein.

The present invention also provides a method for determining acompound's ability to inhibit the aggregation of amyloid proteins. Themethod comprises combining the compound to be tested with amyloidogenicproteins under conditions known to produce amyloid aggregates,introducing into the assay vessel solution a labeled compound of FormulaI, filtering or centrifuging the solution and determining the amount oflabeled compound in the filter or filtrate, or supernatant.

The compounds of Formula I bind amyloid deposits or aggregated amyloidproteins preferentially to soluble pre-amyloid proteins. Thus, if thepre-amyloid proteins in solution aggregate, compounds of Formula I willbind to the aggregates and amyloid deposits and the associated labeledcompound will be retained by the filter. However, if aggregation isinhibited by the compound of interest, then the labeled compound ofFormula I will not bind to the amyloid proteins and will pass throughthe filter.

The compounds to be tested for ability to inhibit the aggregation ofamyloid proteins can be any compound in which one skilled in the artsuspects have amyloid aggregation inhibiting activity or can be chosenat random from a natural product or chemical libraries. The solution canbe any solution in which amyloid proteins, a compound to be tested and acompound of Formula I are soluble. Preferably, the solution is anaqueous solution. The label may be any label known to those skilled inthe art that can be detected and quantitated. For example, a preferredlabel is a radiolabel.

Also provided by the present invention are compounds of Formula Iwherein one or more atom in the compound has been replaced with aradioisotope. The radioisotope can be any radioisotope. However, ³ H,¹²³ I, ¹²⁵ I, ¹³¹ I, ¹¹ C, and ¹⁸ F are preferred.

The compounds of the present invention can be administered to a patientat dosage levels in the range of about 0.1 to about 1,000 mg per day.For a normal human adult having a body weight of about 70 kg, a dosagein the range of about 0.01 to about 100 mg per kilogram of body weightper day is sufficient. The specific dosage used, however, can vary. Forexample, the dosage can depend on a number of factors including therequirements of the patient, the severity of the condition beingtreated, and the pharmacological activity of the compound being used.The determination of optimum dosages for a particular patient is wellknown to those skilled in the art.

The examples presented below are intended to illustrate particularembodiments of the invention and are not intended to limit the scope ofthe specification, including the claims, in any manner.

EXAMPLES Synthesis of Compounds of Formula I and Labeled Compounds ofFormula I Example 1

(E)-{4-[2-(5-Chlorobenzothiazol-2-yl)vinyl]phenyl}dimethylamine

The procedure of Cuadro, et al., Il Farmaco., 47:477-488 (1992), wasfollowed. A suspension of 2-methyl-5-chloro-benzothiazole (3.78 g, 20.6mmol), 4-(dimethylamino)benzaldehyde (3.04 g, 20.4 mmol), and 0.5 g ofbenzyltriethylammonium chloride in 30 mL of 50% aqueous sodium hydroxidesolution was mechanically stirred in an ultrasonic bath at roomtemperature for 12 hours. Water (20 mL) was added, the mixture wascooled, filtered, and the solid was washed with water to give the titlecompound as a yellow solid, mp 182-184° C.

Example 2

(E)-{4-[2-(Benzothiazol-2-yl)vinyl]phenyl}dimethylamine was purchasedfrom the Aldrich Chemical Co.

In a process analogous to Example 1, using appropriately substituted2-methylbenzothiazoles, the corresponding compounds were prepared asfollows:

Example 3

(E)-Dimethyl-{4-[2-(5-methylbenzothiazol-2-yl)vinyl]phenyl}amine, mp192-194° C.

Example 4

(E)-Dimethyl-{4-[2-(6-methylbenzothiazol-2-yl)vinyl]phenyl}amine, mp219-220.5° C.

Example 5

(E)-{2-[2-(4-Dimethylaminophenyl)vinyl]benzothiazol-6-yl}dimethylamine,mp 237-240° C.

Example 6

(E)-3-Benzyl-2-[2-(4-dimethylaminophenyl)vinyl]benzothiazol-3-iumbromide

Step (a) 3-Benzyl-2-methylbenzothiazolium bromide

A solution of 2-methylbenzothiazole (5.0 g, 0.033 mol) and benzylbromide (40 mL, 0.33 mol) in 250 mL of ethyl acetate was refluxed undernitrogen for 48 hours. Solid had formed. The mixture was filtered andwashed with cold ethyl acetate to give3-benzyl-2-methylbenzothiazol-3-ium bromide as a light yellow solid, mp230-231° C.

Step (b)(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-benzylbenzothiazol-3-iumbromide

A mixture of 3-benzyl-2-methylbenzothiazol-3-ium bromide (0.30 g, 0.94mmol) and 4-dimethylaminobenzaldehyde (0.21 g, 1.41 mmol) in 5 mL ofacetic anhydride was heated under nitrogen. Upon refluxing, the mixtureturned red and all solids appeared to be in solution. The solution wasrefluxed for 15 minutes, cooled, and filtered. The solid was washed withethyl acetate to give(E)-2-[2-(4-dimethylaminophenyl)vinyl]-3-benzylbenzothiazol-3-iumbromide as a purple solid, mp 247-248° C., decomposed (dec).

Example 7

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-ethylbenzothiazol-3-ium iodidewas purchased from the Aldrich Chemical Co.

Example 8

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-1-methylnaphtho[1,2-d]thiazol-3-iumiodide was purchased from the Sigma Chemical Co.

In a process analogous to Example 2, appropriately substituted2-methylbenzothiazoles were alkylated with various alkyl halides thencondensed with 4-dimethylaminobenzaldehyde in acetic anhydride, thecorresponding compounds were prepared as follows:

Example 9

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-methylbenzothiazol-3-iumiodide, 251-254° C., dec.

Example 10

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-allylbenzothiazol-3-iumbromide, 237-240° C., dec.

Example 11

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-butylbenzothiazol-3-ium iodide,234-235° C., dec.

Example 12

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-heptylbenzothiazol-3-iumiodide, 228-229° C., dec.

Example 13

(E)-5-Chloro-2-[2-(4-dimethylaminophenyl)vinyl]-3-methylbenzothiazol-3-iumiodide, 260-261° C., dec.

Example 14

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-5-fluoro-3-methylbenzothiazol-3-iumiodide, 250-251° C.

Example 15

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-benzyl-5-fluorobenzothiazol-3-iumbromide, 243-245° C.

Example 16

(E)-2-[2-(4-Dimethylaminophenylvinyl]-3,5-dimethylbenzothiazol-3-iumiodide, 248-250° C., dec.

Example 17

(E)-2-[2-(4-Dimethylaminophenylvinyl]-3,6-dimethylbenzothiazol-3-iumiodide, >240° C., dec.

Example 18

(E)-3-Benzyl-2-[2-(4-dimethylaminophenyl)vinyl]-6-methylbenzothiazol-3-iumbromide, 245-247° C., dec.

Example 19

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-6-methoxy-3-methylbenzothiazol-3-iumiodide, 254-260° C., dec.

Example 20

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-heptyl-6-methoxybenzothiazol-3-iumiodide, 207-208° C., dec.

Example 21

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-methyl-6-nitrobenzothiazol-3-iumtoluene-4-sulfonate, 281-282° C., dec.

Example 22

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-1-ethylnaphtho[1,2-d]thiazol-3-iumtoluene-4-sulfonate, >186° C., dec.

Example 23

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-methylnaphtho[2,3-d]thiazol-3-iumiodide, 302-303° C., dec.

Example 24

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-methylnaphtho[2,1-d]thiazol-3-iumiodide, 245-247° C., dec.

Example 25

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(4-fluorobenzyl)benzothiazol-3-iumbromide, 254-255° C.

Example 26

(E)-3-Biphenyl-4-ylmethyl-2-[2-(4-dimethylaminophenyl)vinyl]benzothiazol-3-iumiodide, 210-213° C.

Example 27

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-naphthalen-2-ylmethylbenzothiazol-3-iumbromide, 233-236° C.

Example 28

(E)-3-Biphenyl-2-ylmethyl-2-[2-(4-dimethylaminophenyl)vinyl]benzothiazol-3-iumbromide, 229-230° C.

Example 29

(E)-3-(3-Benzoylbenzyl)-2-[2-(4-dimethylaminophenyl)vinyl]benzothiazol-3-iumbromide, 231-233° C.

Example 30

(E)-2-[2-(4-Dimethylaminophenylvinyl]-3-(3-phenoxybenzyl)benzothiazol-3-iumbromide, 231-232° C.

Example 31

(E)-2-[2-(4-Dimethylaminophenylvinyl]-3-(3-phenylpropyl)benzothiazol-3-iumiodide, 268-269° C.

Example 32

(E,E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(3-phenylallyl)benzothiazol-3-iumbromide, 220-222° C.

Example 33

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(4,4-diphenylbutyl)benzothiazol-3-iumiodide, 187-189° C.

Example 34

(E)-3-(3-Benzyloxypropyl)-2-[2-(4-dimethylaminophenylvinyl]benzothiazol-3-iumiodide, 174-177° C.

Example 35

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(4-phenoxybutyl)benzothiazol-3-iumiodide, 165-170° C., dec.

Example 36

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(5-phenylpentyl)benzothiazol-3-iumiodide, 214-217° C.

Example 37

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(5-phenoxypentyl)benzothiazol-3-iumiodide, 156-158.5° C.

Example 38

(E)-3-(2-Cyclohexylethyl)-2-[2-(4-dimethylaminophenyl)vinyl]benzothiazol-3-iumiodide, 262-264° C.

Example 39

(E)-2-[2-(4-Dimethylaminonaphthalen-1-yl)vinyl]-3-heptylbenzothiazol-3-iumiodide

Step (a) 3-Heptyl-2-methylbenzothiazolium iodide

A solution of 2-methylbenzothiazole (10.0 g, 0.067 mol) and1-iodoheptane (110 mL, 0.67 mol) in 100 mL of acetronitrile was refluxedunder nitrogen for 48 hours. The mixture was cooled, filtered, and thesolid formed was washed with diethyl ether and recrystallized fromethanol-ethyl acetate to give 3-heptyl-2-methylbenzothiazolium iodide asa light purple solid, mp 110-113° C.

Step (b)(E)-2-[2-(4-Dimethylaminonaphthalen-1-yl)vinyl]-3-heptylbenzothiazol-3-iumiodide

A mixture of 3-heptyl-2-methylbenzothiazolium iodide (0.50 g, 1.33 mmol)and 4-dimethylamino-1-naphthaldehyde (0.40 g, 2.01 mmol) in 5 mL ofacetic anhydride under nitrogen was heated. Upon refluxing, the mixtureturned purple and all solids seemed to be in solution. The solution wasrefluxed for 15 minutes and on cooling, solid formed. The mixture wasfiltered and washed with ethyl acetate to give(E)-2-[2-(4-dimethylaminonaphthalen-1-yl)vinyl]-3-heptylbenzothiazol-3-iumiodide as a dark brown solid, mp 195-197° C.

Example 40

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(2-hydroxyethyl)benzothiazol-3-iumbromide was purchased from the Eastman Kodak Co.

In a process analogous to Example 3, using appropriately substituted2-methylbenzothiazoles, alkyl halides, and benzaldehydes, thecorresponding compounds were prepared as follows:

Example 41

(E)-2-[2-(4-Dimethylaminonaphthalen-1-yl)vinyl]-6-methoxy-3-methylbenzothiazol-3-iumiodide, 246-247° C., dec.

Example 42

(E)-2-[2-(4-Dimethylaminonaphthalen-1-yl)vinyl]-1-1-methylnaphtho[1,2-d]thiazol-1-iumtoluene-4-sulfonate, 200-210° C.

Example 43

(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-methylbenzothiazol-3-iumchloride, 188-190° C., dec.

Example 44

(E)-2-[2-(4-Diethylaminophenyl)vinyl]-3-heptylbenzothiazol-3-ium iodide,201-202° C., dec.

Example 45

(E)-2-[2-(4-Dibutylaminophenyl)vinyl]-3-heptylbenzothiazol-3-ium iodide,163-164° C.

Example 46

(E)-3-Heptyl-2-[2-[(4-pyrrolidin-1-yl)phenyl]vinyl]benzothiazol-3-iumiodide, 227-229° C., dec.

Example 47

[4-(Dimethylamino)phenylazo]benzothiazole

An ice-cold solution of sodium nitrite (1.65 g, 23.9 mmol) in water (15mL) was added slowly (via syringe) to a stirring mixture at 0° C. of2-aminobenzothiazole (3.78 g, 25.2 mmol) in water (50 mL) andconcentrated sulfuric acid (7.0 mL, 126.7 mmol). During addition, thetemperature was kept below 5° C. The resultant orange mixture wasstirred at 0° C. for 15 minutes, then N,N-dimethylaniline was addeddropwise causing the mixture to turn dark brown-black. The mixture wasstirred at 0° C. for 15 minutes, an aqueous solution of sodium acetate(4.32 g in 20 mL of water) was added dropwise, stirred for 1 hour,basified with 25% sodium hydroxide solution to a pH ˜12 and allowed towarm to room temperature. The mixture was filtered, the solid was washedwith cold water, recrystallized from methanol, then chromatographed(silica gel, 2% methanol in methylene chloride) to give the titlecompound as a green solid, mp 243-246° C.

In a process analogous to Example 4, using appropriately substituted2-aminobenzothiazoles and arylamines, the corresponding compounds wereprepared as follows:

Example 48

4-(Benzothiazol-2-ylazo)naphthalen-1-ylamine

Example 49

2-[[4-(Dimethylamino)phenyl]azo]-6-methoxybenzothiazole, 213-216° C.

Example 50

6-Chloro-2-[[4-(dimethylamino)phenyl]azo]benzothiazole, 214-218° C.

Example 51

[4-(6-Methoxybenzothiazol-2-ylazo)naphthalen-1-yl]dimethylamine,185-185° C.

Example 52

Dimethyl[4-(naphtho[1,2-d]thiazol-2-ylazo)naphthalen-1-yl]amine,146-148° C.

Example 53

2-[[4-(Dimethylamino)phenyl]azo]-6-methoxy-3-methylbenzothiazol-3-iummethylsulfate

A solution of [4-(6-methoxy-benzothiazol-2-ylazo)phenyl]-dimethyl-amine(Example 4b, 0.75 g, 2.40 mmol) and dimethyl sulfate (0.50 mL, 5.28mmol) in 15 mL of chlorobenzene was heated under nitrogen at 70° C. for3 hours. The solution was cooled and solid formed. The mixture wasfiltered, the solid was washed with diethyl ether and recrystallizedfrom ethanol to give the title compound as a dark blue-black solid, mp206-207° C., dec.

Example 54

2-[[4-(Dimethylamino)phenyl]azo]-3-methylbenzothiazolium methylsulfatewas purchased from the Tennessee Eastman Co.

Tritiation of Example 12 ##STR15## 2-Bromo-4-(dimethylamino)benzaldehyde

To a solution of 4-(dimethylamino)benzaldehyde (5.0 g, 33.5 mmol) inchloroform (30 mL) was added benzoyl peroxide (10 mg). Bromine (5.43 g,34 mmol) in chloroform (10 mL) was added dropwise to the solution ofaldehyde over a 30 minute period. The reaction was stirred an additionalhour, and the chloroform solution was washed with 5% NaHCO₃, dried(MgSO₄), and concentrated. The crude oil was chromatographed on a silicagel column eluted with methylene chloride to yield the product as a paleyellow oil (5.21 g, 68% yield).

Analysis calculated for C₉ H₁₀ BrNO: C, 47.39; H, 4.42; N, 6.14. Found:C, 47.08; H, 4.38; N, 6.13.

Tritiation of 2-bromo-4-(dimethylamino)benzaldehyde

To a solution of the 2-bromo-4-(dimethylamino)benzaldehyde (0.02 g) inanhydrous tetrahydrofuran was added 10% Pd/C (12 mg). The reaction wasstirred under an atmosphere of tritium gas for 18 hours. The gas wasremoved using a gas manifold at -78° C., and the reaction was filteredthrough a Celite pad and concentrated. Methanol was added (3×20 mL), andthe reaction was reconcentrated to remove any exchangeable tritium. Theoil was partitioned between methylene chloride and 5% NaHCO₃. Themethylene chloride layer was dried (MgSO₄), filtered, and concentrated.The crude product was chromatographed on a silica gel column eluted withmethylene chloride. The unreacted starting material came off firstfollowed by the tritiated 4-(dimethylamino)benzaldehyde. The product wasused without additional purification or characterization.

[³ H]-(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-heptylbenzothiazol-3-iumiodide

The procedure used to prepare Example 44 was applied to the reaction of[³ H]-4-(dimethylamino)benzaldehyde with3-heptyl-2-methylbenzothiazolium iodide to give the title compoundsspecific activity 20.54 Ci/mmol.

Example of ¹³¹ I-Labeling ##STR16## Example of ¹¹ C-Labeling ##STR17##Example of ¹⁸ F-Labeling ##STR18##

A and B are known in the art or can be prepared by known methods.

The preferred solvent is water or other polar solvents (methanol, H₂O/methanol mixtures, etc.);

"Base" can be NaOH, KOH, LiOH, etc., in the presence of a phase-transfercatalyst, such as PhCHeNEt₃ Cl and other tetraalkylammonium halides.

(2) When X═Y is C═C and R₃ is anything other than a lone pair ofelectrons: ##STR19## Where L is a leaving group (Br, Cl, p-toulenesulfonate (TSO), etc.); Where solvent (1) can be any solvent that thecompounds are soluble in, such as ethyl acetate, acetonitrile, ethanol,isopropanol, etc. A preferred solvent (such as ethyl acetate) is onewhere intermediate A crystallizes as it is formed;

Temp (1): room temperature→reflux. Preferred temperature range 40-90°C.;

Solvent (2): one in which A is soluble in and which is dehydrating, suchas acetic anhydride;

Temp (2): Typically, the boiling point of solvent (2). Preferredtemperature range 80-120° C.

(3) When X═Y is N═N, and ##STR20##

(4) When X═Y is N═N, and R₃ is anything other than a lone pair ofelectrons: ##STR21## Where L is a leaving group (Cl, Br, TSO,mesylate(MSO), etc.); Solvent can be any inert solvent, preferably onein which the product crystallizes as it is formed: chlorobenzene,toluene, etc.;

Preferred temperature range 50-100° C.

Synthesis of Amyloid Aggregates

Amyloid aggregates were prepared according to methods that are wellknown to those skilled in the art, and the presence of amyloid fibrinaggregates was verified by Congo Red birefringence, a method that isalso well known to those skilled in the art.

Insulin Amyloid Aggregates

Burke M. J. and Rougevie M. A., Cross-β Protein Structures. I. InsulinFibrils. Biochemistry, 11:2435-243 (1972), which is hereby incorporatedby reference, is an example that shows how to make amyloid aggregateshaving insulin as a component. Briefly, lyophilized insulin proteinpowder dissolved at 10 mg/mL in 50 mM HCl was alternately heated to 95°C. and frozen in dry ice to form amyloid aggregates.

β(1-40) Amyloid Aggregates

Amyloid aggregates containing β(1-40) protein can also be made bymethods well known to those skilled in the art. See, for example,Burdick D., Soreghan B., Kwon M., Kosmoski J., Knauer M., Henschen A.,Yates J., Cotman C., and Glabe C. Assembly and aggregation properties ofsynthetic Alzheimer's A4/β amyloid peptide analogs. J. Biol. Chem.,267:546-554 (1992), which is hereby incorporated by reference. Briefly,lyophilized β(1-40) protein powder (which may be purchased from BACHEM)was dissolved at 10 mg/mL in hexafluoro-2-propanol and subsequentlydiluted to 500 μg/mL in 25 mM sodium phosphate buffer, pH 6 to inducethe α-helix to β-sheet transition resulting in aggregate formation.

Competition Assay

The ability of compounds of Formula I to compete with Thioflavin T (ThT)for binding to amyloid aggregates was measured using fluorescence in a96-well fluorescence plate assay. As a compromise between sensitivityand signal and to facilitate comparisons between different amyloidfibrils, ThT is present at a concentration equal to the K_(mapp) of theparticular amyloid fibril type and fibril concentrations yielding asimilar fluorescence intensity are used. Insulin: 0.5 μM ThT, 2 μg perwell. β(1-40): 20 μM ThT, 5 μg/well. All solutions are in 25 mM sodiumphosphate buffer, pH 6.0, and the assay is performed at roomtemperature.

Using a multichannel pipettor, 100 μL of dilutions of the compound to betested (0.001-30 μM final concentration in 3-fold steps) are placed inthe bottom of Corning U-well polystyrene plates (Corning Company,Corning, N.Y.). 50 μL of ThT are then added to each well. The amyloidfibrils are then added to each well in a volume of 100 μL rapidly to mixthe well contents. The plates are read within 5 to 30 minutes in aMillipore Cytofluor 2350 96-well fluorescence plate reader using anexcitation filter of 440 nm (20 nm bandpass) and an emission filter of485 nm (20 nm bandpass). ThT dye blanks were used to correct for theminimal fluorescence background which are subtracted from all data.Amyloid fibrils do not contribute significantly to the observed signal.Settling of amyloid fibrils does not effect the observed fluorescence asthe instrument reads through the bottom of the sample wells.

Results are expressed as % maximal fluorescence (no competing compound).IC₅₀ s are defined as the concentration of compound required to reduceThT fluorescence to 50% of its initial intensity and are estimated bylog-logit analysis. The data is shown below in Table 1.

                  TABLE 1                                                         ______________________________________                                        Example                   βA(1-40),                                                                         Insulin,                                     Number Name IC.sub.50 (nM) IC.sub.50 (nM)                                   ______________________________________                                        1       (E)-{4-[2-(5-Chlorobenzo-                                                                       >100,000 100,000                                       thiazol-2-yl)vinyl]-                                                          phenyl}dimethylamine                                                         2 (E)-{4-[2-Benzothiazol- >100,000 1,200                                       2-yl)vinyl])phenyl}- (F)                                                      dimethylamine                                                                3 (E)-Dimethyl-{4-[2-(5- (F) 900                                               methylbenzothiazol-2-yl) -  (F)                                               vinyl]phenyl}amine                                                           4 (E)-Dimethyl-{4-[2-(6- (F) 1,500                                             methylbenzothiazol-2-yl)-  (F)                                                vinyl]phenyl}amine                                                           5 (E)-{2-[2-(4-Dimethylamino- >100,000 6,000                                   phenyl)vinyl]benzothiazol-                                                    6-yl}dimethylamine                                                           6 (E)-3-Benzyl-2-[2-(4- 110 12                                                 dimethylaminophenyl)-                                                         vinyl]benzothiazol-3-ium                                                      bromide                                                                      7 (E)-2-[2-(4-Dimethylamino- 400 6                                             phenyl)vinyl]-3-ethylbenzo-                                                   thiazol-3-ium iodide                                                         8 (E)-2-[2-(4-Dimethylamino- 210 53                                            phenyl)vinyl]-1-                                                              methylnaphtho[1,2-d]-                                                         thiazol-3-ium iodide                                                         9 (E)-2-[2-(4-Dimethyl- 1,000 3                                                aminophenyl)vinyl[-3-                                                         methylbenzothiazol-3-ium                                                      iodide                                                                       10 (E)-2-[2-(4-Dimethyl- 300 12                                                aminophenyl)vinyl[-3-                                                         allylbenzothiazol-3-ium                                                       bromide                                                                      11 (E)-2-[2-(4-Dimethyl- 160 27                                                aminophenyl)vinyl]-3-                                                         butylbenzothiazol-3-ium                                                       iodide                                                                       12 (E)-2-[2-(4-Dimethyl- 93 83                                                 aminophenyl)vinyl]-3-                                                         heptylbenzothiazol-3-ium                                                      iodide                                                                       13 (E)-5-Chloro-2-[2-(4- 430 5.2                                               dimethylaminophenyl)-                                                         vinyl]-3-methylbenzo-                                                         thiazol-3-ium iodide                                                         14 (E)-2-[2-(4-Dimethyl- 1,000 10                                              aminophenyl)vinyl]-5-                                                         fluoro-3-methylbenzo-                                                         thiazol-3-ium iodide                                                         15 (E)-2-[2-(4-Dimethyl- 170 32                                                aminophenyl)vinyl]-3-                                                         benzyl-5-fluorobenzo-                                                         thiazol-3-ium bromide                                                        16 (E)-2-[2-(4-Dimethyl- 400 7.5                                               aminophenyl)vinyl]-3,5-                                                       dimethylbenzothiazol-3-ium                                                    iodide                                                                       17 (E)-2-[2-(4-Dimethyl- 180 6                                                 aminophenyl)vinyl]-3,6-                                                       dimethylbenzothiazol-3-ium                                                    iodide                                                                       18 (E)-3-Benzyl-2-[2-(4- 130 50                                                dimethylaminophenyl)-                                                         vinyl]-6-methylbenzo-                                                         thiazol-3-ium bromide                                                        19 (E)-2-[2-(4-Dimethyl- 300 8                                                 aminophenyl)vinyl]-6-                                                         methoxy-3-methylbenzo-                                                        thiazol-3-ium iodide                                                         20 (E)-2-[2-(4-Dimethyl- 140 40                                                aminophenyl)vinyl]-3-                                                         heptyl-6-methoxybenzo-                                                        thiazol-3-ium iodide                                                         21 (E)-2-[2-(4-Dimethyl- 1,000 12                                              aminophenyl)vinyl]-3-                                                         methyl-6-nitrobenzo-                                                          thiazol-3-ium toluene-4-                                                      sulfonate                                                                    22 (E)-2-[2-(4-Dimethyl- 210 41                                                aminophenyl)vinyl]-1-                                                         ethylnaphtho[1,2-d]-                                                          thiazol-1-ium toluene-4-                                                      sulfonate                                                                    23 (E)-2-[2-(4-Dimethyl- 120 120                                               aminophenyl)vinyl]-3-                                                         methylnaphtho[2,3-d]-                                                         thiazol-3-ium iodide                                                         24 (E)-2-[2-(4-Dimethyl- 210 41                                                aminophenyl)vinyl]-3-                                                         methylnaphtho[2,1-d]-                                                         thiazol-3-ium iodide                                                         25 (E)-2-[2-(4-Dimethyl- 120 42                                                aminophenyl)vinyl]-3-(4-                                                      fluorobenzyl)benzothiazol-                                                    3-ium bromide                                                                26 (E)-3-Biphenyl-4-ylmethyl- 240 34                                           2-[2-(4-dimethylamino-                                                        phenyl)vinyl]benzothiazol-                                                    3-ium iodide                                                                 27 (E)-2-[2-(4-Dimethyl- 120 13                                                aminophenyl)vinyl]-3-                                                         naphthalen-2-ylmethyl-                                                        benzothiazol-3-ium bromide                                                   28 (E)-3-Biphenyl-2-ylmethyl- 100 80                                           2-[2-(4-dimethylamino-                                                        phenyl)vinyl]benzothiazol-                                                    3-ium bromide                                                                29 (E)-3-(3-Benzoylbenzyl)-2- 230 130                                          [2-(4-dimethylaminophenyl)-                                                   vinyl[benzothiazol-3-ium                                                      bromide                                                                      30 (E)-2-[2-(4-Dimethylamino- 120 180                                          phenyl)vinyl]-3-(3-                                                           phenoxybenzyl)benzothiazol-                                                   3-ium bromide                                                                31 (E)-2-[2-(4-Dimethyl- 200 210                                               aminophenyl)vinyl]-3-(3-                                                      phenylpropyl)benzothiazol-                                                    3-ium iodide                                                                 32 (E-E)-2-[2-(4-Dimethyl- 100 80                                              aminophenyl)vinyl]-3-(3-                                                      phenylallyl)benzothiazol-3-                                                   ium bromide                                                                  33 (E)-2-[2-(4-Dimethyl- 460 210                                               aminophenyl)vinyl]-3-(4,4-                                                    diphenylbutyl)benzothiazol-                                                   3-ium iodide                                                                 34 (E)-3-(3-Benzyloxypropyl)- 140 52                                           2-[2-(4-dimethylamino-                                                        phenyl)vinyl]benzothiazol-                                                    3-ium iodide                                                                 35 (E)-2-[2-(4-Dimethyl- 170 62                                                aminophenyl)vinyl]-3-(4-                                                      phenoxybutyl)benzothiazol-                                                    3-ium iodide                                                                 36 (E)-2-[2-(4-Dimethyl- 170 93                                                aminophenyl)vinyl]-3-(5-                                                      phenylpentyl)benzothiazol-                                                    3-ium iodide                                                                 37 (E)-2-[2-(4-Dimethyl- 170 80                                                aminophenyl)vinyl]-3-(5-                                                      phenoxypentyl)benzothiazol-                                                   3-ium iodide                                                                 38 (E)-3-(2-Cyclohexylethyl)- 120 52                                           2-[2-(4-dimethylamino-                                                        phenyl)vinyl]benzothiazol-                                                    3-ium iodide                                                                 39 (E)-2-[2-(4-Dimethyl- 160 40                                                aminonaphthalen-1-yl)-                                                        vinyl]-3-heptylbenzo-                                                         thiazol-3-ium iodide                                                         41 (E)-2-[2-(4-Dimethyl- 430 26                                                aminonaphthalen-1-yl)-                                                        vinyl]-6-methoxy-3-                                                           methylbenzothiazol-3-ium                                                      iodide                                                                       42 (E)-2-[2-(4-Dimethylamino- 250 42                                           naphthalen-1-yl)vinyl]-1-                                                     methylnaphtho[1,2-d]-                                                         thiazol-1-ium toluene-4-                                                      sulfonate                                                                    43 (E)-2-[2-(4-Dimethylamino-                                                  phenyl)vinyl]-3-methyl-                                                       benzothiazol-3-ium chloride                                                  44 (E)-2-[2-(4-Diethylamino- 140 120                                           phenyl)vinyl]-3-heptyl-                                                       benzothiazol-3-ium iodide                                                    45 (E)-2-[2-(4-Dibutylamino- 600 90                                            phenyl)vinyl-3-heptyl-                                                        benzothiazol-3-ium iodide                                                    46 (E)-3-Heptyl-2-[2-[(4 160 42                                                pyrrolidin-1-yl)phenyl]-                                                      vinyl]benzothiazol-3-ium                                                      iodide                                                                       47 [4-(Dimethylamino)- 22,000 1,200                                            phenylazo]benzothiazole                                                      48 4-(Benzothiazol-2-ylazo)- 120 110                                           naphthalen-1-ylamine                                                         49 2-[[4-(Dimethylamino)- 3,200 700                                            phenyl]azo]-6-methoxy-                                                        benzothiazole                                                                50 6-Chloro-2-[[4-(dimethyl- 1,300 1,300                                       amino)phenyl]azo]benzo-                                                       thiazole                                                                     51 [4-(6-Methoxybenzothiazol- 2,500 340                                        2-ylazo)naphthalen-1-yl]-                                                     dimethylamine                                                                52 Dimethyl[4-(naphtho[1,2-d]- 52,000 16,000                                   thiazol-2-ylazo)naphthalen-                                                   1-yl]-amine                                                                  53 2-[[(4-Dimethylamino- 410 10                                                phenyl]azo)-6-methoxy-3-                                                      methylbenzothiazol-3-ium                                                      methylsulfate                                                                54 2-[[(4-Dimethylamino)- 1,300 60                                             phenyl]azo]-3-methylbenzo-                                                    thiazolium methylsulfate                                                   ______________________________________                                         (F) indicates that the test compound itself is fluorescent and interferes     with the assay.                                                          

Binding of [³H]-2-[2-(4-Dimethylaminophenyl)vinyl]-3-heptylbenzothiazol-3-ium iodideto Amyloid Fibrils

The binding reaction is carried out at room temperature in buffer (25 mMsodium phosphate, pH 6.0+0.2 mg/mL chicken ovalbumin (which can bepurchased from Sigma). 33 μL of buffer containing 30,000 cpm of [³H]-2-[2-(4-Dimethylaminophenyl)vinyl]-3-heptylbenzothiazol-3-ium iodideare added to 33 μL of diluted test compound in buffer in polyallomer 1.5mL microfuge tubes (which may be purchased from Beckman). The bindingreaction is initiated with 33 μL of buffer containing 300 ng of insulinamyloid fibrils and vortexing. After 45 minutes, 1.25 mL of buffer areadded to each tube, vortexed, and spun at 16,000×G in a microfuge for 10minutes. The supernatant is removed by pasteur pipet and the whole tubeis placed in a 20 mL scintillation vial for determination of tritiumafter the addition of Ready-Gel scintillation fluid (Beckman).Nonspecific binding of label to tubes containing no amyloid fibrils orwith fibrils in the presence of excess unlabeled2-[2-(4-dimethylaminophenyl)vinyl]-3-heptylbenzothiazol-3-ium iodidegive the same values and are subtracted from the total binding to obtainspecific binding.

Results are expressed as % maximal specific binding. IC₅₀ s are definedas the concentration of compound required to reduce [³H]-2-[2-(4-dimethylaminophenyl)vinyl]-3-heptyl benzothiazol-3-ium iodidebinding to 50% of its initial amount and are estimated by log-logitanalysis. FIGS. 1 and 2 show the results.

We claim:
 1. A method of imaging amyloid deposits, the methodcomprising:a. introducing into a patient a detectable quantity of alabeled compound having the Formula I or a pharmaceutically acceptablesalt, ester, or amide thereof ##STR22## wherein X and Y are eachindependently C or N and the X═Y double bond has the transconfiguration; Z is ##STR23## R¹ and R² are each independently hydrogen,C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, amino, di(C₁ -C₆alkyl)amino, mono(C₁ -C₆ alkyl)amino, nitro, C₁ -C₆ thioalkoxy, or R¹and R² combined form a benzene, cyclopentane, or cyclohexane ring thatis fused to the phenyl ring; R³ is a lone pair of electrons, C₁ -C₁₀alkyl, C₂ -C₁₀ alkenyl, arylalkyl, (heteroaryl)alkyl, (cycloalkyl)alkyl,arylalkenyl, diarylalkyl or --(CH₂ )_(m) --A--(CH 2)_(n) --Q; m is 1 to6 and n is 0 to 6; A is --O--, --S--, --NR⁴⁻, C═O, or a single bond; Qis phenyl substituted with R⁷ or naphthyl substituted with R⁷ ; R⁷ ishydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, amino, di(C₁-C₆ alkyl)amino, nitro, C₁ -C₆ thioalkoxy, aryl, heteroaryl, aryloxy,--CO-aryl, or arylthio; R⁴ and R⁵ are each independently hydrogen, C₁-C₆ alkyl or --NR⁴ R⁵ represents a 5-, 6- or 7-membered ring containingnitrogen; and R⁶ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy,halogen, amino, di(C₁ -C₆ alkyl)amino, nitro, or C₁ -C₆ thioalkoxy; b.allowing sufficient time for the labeled compound to become associatedwith amyloid deposits; and c. detecting the labeled compound associatedwith the amyloid deposits.
 2. The method of claim 1 whereinX═Y is C═C orN═N; R¹ and R² are each independently hydrogen, C₁ -C₆ alkyl, C₁ -C₆alkoxy, halogen, nitro, C₁ -C₆ thioalkoxy, or R¹ and R² combined form abenzene, cyclopentane or cyclohexane ring that is fused to the phenylring; R³ is C₁ -C₁₀ alkyl, C₂ -C₁₀ alkenyl, arylalkyl,(cycloalkyl)alkyl, arylalkenyl, diarylalkenyl, or --(CH₂)_(m)--A--(CH₂)_(n) --Q; m is 1 to 5 and n is 0 to 4; A is --O--, --S--, or asingle bond; Q is phenyl substituted with R⁷ or naphthyl substitutedwith R⁷ ; R⁷ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen,amino, di(C₁ -C₆ alkyl)amino, nitro, C₁ -C₆ thioalkoxy, aryl, aryloxy,--CO-aryl, or arylthio; R⁴ and R⁵ are each independently hydrogen or C₁-C₆ alkyl; and R⁶ is hydrogen, C₁ -C₆ alkyl, or halogen.
 3. The methodof claim 1 whereinX═Y is C═C or N═N; R¹ and R² are each independentlyhydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, halogen, nitro, or R¹ and R²combined form a (4,5), (5,6), or (6,7) benzene ring that is fused to thephenyl ring; R³ is C₁ -C₁₀ alkyl, C₂ -C₁₀ alkenyl, arylalkyl,arylalkenyl, diarylalkyl, or --(CH₂)_(m) --A--(CH₂)_(n) --Q; m is 2 to 4and n is 0 to 3; A is --O--, or a single bond; Q is phenyl substitutedwith R⁷ or naphthyl substituted with R⁷ ; R⁷ is hydrogen, C₁ -C₆ alkyl,C₁ -C₆ alkoxy, hydroxy, halogen, aryl, aryloxy, or --CO-aryl; R⁴ and R⁵are each independently hydrogen, methyl, ethyl, n-propyl or n-butyl; andR⁶ is hydrogen or halogen.
 4. The method of claim 1 wherein the compoundis(E)-{4-[2-(5-Chlorobenzothiazol-2-yl)vinyl]phenyl}dimethylamine;(E)-{4-[2-Benzothiazol-2-yl)vinyl])phenyl}dimethylamine;(E)-Dimethyl-{4-[2-(5-methylbenzothiazol-2-yl)vinyl]phenyl}amine;(E)-Dimethyl-{4-[2-(6-methylbenzothiazol-2-yl)vinyl]phenyl}amine;(E)-{2-[2-(4-Dimethylaminophenyl)vinyl]benzothiazol-6-yl}dimethylamine;(E)-3-Benzyl-2-[2-(4-dimethylaminophenyl)vinyl]benzothiazol-3-iumbromide;(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-ethylbenzothiazol-3-ium iodide;(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-1-methylnaphtho[1,2-d]thiazol-3-iumiodide;(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-methylbenzothiazol-3-iumiodide; (E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-allylbenzothiazol-3-iumbromide;(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-butylbenzothiazol-3-ium iodide;(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-heptylbenzothiazol-3-iumiodide;(E)-5-Chloro-2-[2-(4-dimethylaminophenyl)vinyl]-3-methylbenzothiazol-3-iumiodide;(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-5-fluoro-3-methylbenzothiazol-3-iumiodide;(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-benzyl-5-fluorobenzothiazol-3-iumbromide;(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3,5-dimethylbenzothiazol-3-iumiodide;(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3,6-dimethylbenzothiazol-3-iumiodide;(E)-3-Benzyl-2-[2-(4-dimethylaminophenyl)vinyl]-6-methylbenzothiazol-3-iumbromide;(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-6-methoxy-3-methylbenzothiazol-3-iumiodide;(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-heptyl-6-methoxybenzothiazol-3-iumiodide;(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-methyl-6-nitrobenzothiazol-3-iumtoluene-4-sulfonate;(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-1-ethylnaphtho[1,2-d]thiazol-1-iumtoluene-4-sulfonate;(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-methylnaphtho[2,3-d]thiazol-3-iumiodide;(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-methylnaphtho[2,l-d]thiazol-3-iumiodide;(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(4-fluorobenzyl)benzothiazol-3-iumbromide;(E)-3-Biphenyl-4-ylmethyl-2-[2-(4-dimethylaminophenyl)vinyl]benzothiazol-3-iumiodide;(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-naphthalen-2-ylmethylbenzothiazol-3-iumbromide;(E)-3-Biphenyl-2-ylmethyl-2-[2-(4-dimethylaminophenyl)vinyl]benzothiazol-3-iumbromide;(E)-3-(3-Benzoylbenzyl)-2-[2-(4-dimethylaminophenyl)vinyl]benzothiazol-3-iumbromide;(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(3-phenoxybenzyl)benzothiazol-3-iumbromide(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(3-phenylpropyl)benzothiazol-3-iumiodide;(E,E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(3-phenylallyl)benzothiazol-3-iumbromide;(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(4,4-diphenylbutyl)benzothiazol-3-iumiodide;(E)-3-(3-Benzyloxypropyl)-2-[2-(4-dimethylaminophenyl)vinyl]benzothiazol-3-iumiodide;(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(4-phenoxybutyl)benzothiazol-3-iumiodide;(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(5-phenylpentyl)benzothiazol-3-iumiodide;(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(5-phenoxypentyl)benzothiazol-3-iumiodide;(E)-3-(2-Cyclohexylethyl)-2-[2-(4-dimethylaminophenyl)vinyl]benzothiazol-3-iumiodide;(E)-2-[2-(4-Dimethylaminonaphthalen-1-yl)vinyl]-3-heptylbenzothiazol-3-iumiodide;(E)-2-[2-(4-Dimethylaminophenyl)vinyl]-3-(2-hydroxyethyl)benzothiazol-3-iumbromide;(E)-2-[2-(4-Dimethylaminonaphthalen-1-yl)vinyl]-6-methoxy-3-methylbenzothiazol-3-iumiodide;(E)-2-[2-(4-Dimethylaminonaphthalen-1-yl)vinyl]-1-methylnaphtho[1,2-d]thiazol-1-iumtoluene-4-sulfonate;(E)-2-[2-(4-Diethylaminophenyl)vinyl]-3-methylbenzothiazol-3-iumchlordide;(E)-2-[2-(4-Dibethylaminophenyl)vinyl]-3-heptylbenzothiazol-3-iumiodide; (E)-2-[2-(4-Dibutylaminophenyl)vinyl]-3-heptylbenzothiazol-3-iumiodide;(E)-3-Heptyl-2-[2-[(4-pyrrolidin-1-yl)phenyl]vinyl]benzothiazol-3-iumiodide; [4-(Dimethylamino)phenylazo]benzothiazole;4-(Benzothiazol-2-ylazo)naphthalen-1-ylamine;2-[[4-(Dimethylamino)phenyl]azo]-6-methoxybenzothiazole;6-Chloro-2-[[4-(dimethylamino)phenyl]azo]benzothiazole;[4-(6-Methoxybenzothiazol-2-ylazo)naphthalen-1-yl]dimethylamine;Dimethyl[4-(naphtho[1,2-d]thiazol-2-ylazo)naphthalen-1-yl]amine;2-[[(4-Dimethylamino)phenyl]azo]-6-methoxy-3-methylbenzothiazol-3-iummethylsulfate; and2-[[(4-Dimethylamino)phenyl]azo]-3-methylbenzothiazolium methylsulfate.5. A method of delivering a therapeutic agent to an amyloid depositcomprising introducing into a patient a compound having the formula

    A--B--C

or a pharmaceutically acceptable salt, ester, or amide thereof, whereinA is ##STR24## X and Y are each independently C or N and the X═Y doublebond has the trans configuration; Z is ##STR25## R¹ and R² are eachindependently hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen,amino, di(C₁ -C₆ alkyl)amino, mono(C₁ -C₆ alkyl)amino, nitro, C₁ -C₆thioalkoxy or R¹ and R² combined form a benzene, cyclopentane, orcyclohexane ring that is fused to the phenyl ring; R³ is a lone pair ofelectrons, C₁ -C₁₀ alkyl, C₂ -C₁₀ alkenyl, arylalkyl, (heteroaryl)alkyl,(cycloalkyl)alkyl, arylalkenyl, diarylalkyl or --(CH₂)_(m)--A--(CH₂)_(n) --Q; m is 1 to 6 and n is 0 to 6; A is --O--, --S--,--NR⁴⁻, C═O, or a single bond; Q is phenyl substituted with R⁷ ornaphthyl substituted with R⁷ ; R⁷ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆alkoxy, hydroxy, halogen, amino, di(C₁ -C₆ alkyl)amino, nitro, C₁ -C₆thioalkoxy, aryl, heteroaryl, aryloxy, --CO-aryl or arylthio; R⁴ and R⁵are each independently hydrogen, C₁ -C₆ alkyl or --NR⁴ R⁵ represents a5-, 6-, or 7-membered ring containing nitrogen; and R⁶ is hydrogen, C₁-C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, amino, di(C₁ -C₆alkyl)amino, nitro or C₁ -C₆ thioalkoxy; B is a linking moiety or abond; and C is a therapeutic agent.
 6. The method of claim 5 whereinX═Yis C═C or N═N; R¹ and R² are each independently hydrogen, C₁ -C₆ alkyl,C₁ -C₆ alkoxy, halogen, nitro, C₁ -C₆ thioalkoxy, or R¹ and R² combinedform a benzene, cyclopentane, or cyclohexane ring that is fused to thephenyl ring; R³ is C₁ -C₁₀ alkyl, C₂ -C₁₀ alkenyl, arylalkyl,(cycloalkyl)alkyl, arylalkenyl, diarylalkyl, or --(CH₂)_(m)--A--(CH₂)_(n) --Q; m is 1 to 5 and n is 0 to 4; A is --O--, --S--, or asingle bond; Q is phenyl substituted with R⁷ or naphthyl substitutedwith R⁷ ; R⁷ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen,amino, di(C₁ -C₆ alkyl)amino, nitro, C₁ -C₆ thioalkoxy, aryl, aryloxy,--CO-aryl, or arylthio; R⁴ and R⁵ are each independently hydrogen or C₁-C₆ alkyl; and R⁶ is hydrogen, C₁ -C₆ alkyl, or halogen.
 7. The methodof claim 5 whereinX═Y is C═C or N═N; R¹ and R² are each independentlyhydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, halogen, nitro, or R¹ and R²combined form a (4,5), (5,6), or (6,7) benzene ring that is fused to thephenyl ring; R³ is C₁ -C₁₀ alkyl, C₂ -C₁₀ alkenyl, arylalkyl,arylalkenyl, diarylalkyl, or --(CH₂)_(m) --A--(CH₂)_(n) --Q; m is 2 to 4and n is 0 to 3; A is --O--, or a single bond; Q is phenyl substitutedwith R⁷ or naphthyl substituted with R⁷ ; R⁷ is hydrogen, C₁ -C₆ alkyl,C₁ -C₆ alkoxy, hydroxy, halogen, aryl, aryloxy, or --CO-aryl; R⁴ and R⁵are each independently hydrogen, methyl, ethyl, n-propyl or n-butyl; andR⁶ is hydrogen or halogen.
 8. The method of claim 5 wherein the patienthas Alzheimer's disease or Down's syndrome.
 9. The method of claim 5wherein the linking moiety is a covalent bond, amino acids, peptide,alkyl chain, hydroxy acid, or diacid.
 10. A method of inhibiting theaggregation of amyloid proteins to form amyloid deposits, the methodcomprising:a. administering to a patient an amyloid protein aggregationinhibiting amount of a compound of Formula I or a pharmaceuticallyacceptable salt, ester, or amide thereof ##STR26## wherein X and Y areeach independently C or N and the X═Y double bond has the transconfiguration; Z is ##STR27## R¹ and R² are each independently hydrogen,C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, amino, di(C₁ -C₆alkyl)amino, mono(C₁ -C₆ alkyl)amino, nitro, C₁ -C₆ thioalkoxy or R¹ andR² combined form a benzene, cyclopentane, or cyclohexane ring that isfused to the phenyl ring; R³ is a lone pair of electrons, C₁ -C₁₀ alkyl,C₂ -C₁₀ alkenyl, arylalkyl, (heteroaryl)alkyl, (cycloalkyl)alkyl,arylalkenyl, diarylalkyl, or --(CH₂)_(m) --A--(CH₂)_(n) --Q; m is 1 to 6and n is 0 to 6; A is --O--, --S--, --NR⁴ , C═O, or a single bond; Q isphenyl substituted with R⁷ or naphthyl substituted with R⁷ ; R⁷ ishydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, amino, di(C₁-C₆ alkyl)amino, nitro, C₁ -C₆ thioalkoxy, aryl, heteroaryl, aryloxy,--CO-aryl, or arylthio; R⁴ and R⁵ are each independently hydrogen, C₁-C₆ alkyl or --NR⁴ R⁵ represents a 5-, 6- or 7-membered ring containingnitrogen; and R⁶ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy,halogen, amino, di(C₁ -C₆ alkyl)amino, nitro, or C₁ -C₆ thioalkoxy. 11.The method of claim 10 whereinX═Y is C═C or N═N; R¹ and R² are eachindependently hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, halogen, nitro, C₁-C₆ thioalkoxy, or R¹ and R² combined form a benzene, cyclopentane, orcyclohexane ring that is fused to the phenyl ring; R³ is C₁ -C₁₀ alkyl,C₂ -C₁₀ alkenyl, arylalkyl, (cycloalkyl)alkyl, arylalkenyl,diarylalkenyl, or --(CH₂)_(m) --A--(CH₂)_(n) --Q; m is 1 to 5 and n is 0to 4; A is --O--, --S--, or a single bond; Q is phenyl substituted withR⁷ or naphthyl substituted with R⁷ ; R⁷ is hydrogen, C₁ -C₆ alkyl, C₁-C₆ alkoxy, hydroxy, halogen, amino, di(C₁ -C₆ alkyl)amino, nitro, C₁-C₆ thioalkoxy, aryl, aryloxy, --CO-aryl, or arylthio; R⁴ and R⁵ areeach independently hydrogen or C₁ -C₆ alkyl; and R⁶ is hydrogen, C₁ -C₆alkyl, or halogen.
 12. The method of claim 10 whereinX═Y is C═C or N═N;R¹ and R² are each independently hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy,halogen, nitro, or R¹ and R² combined form a (4,5), (5,6), or (6,7)benzene ring that is fused to the phenyl ring; R³ is C₁ -C₁₀ alkyl, C₂-C₁₀ alkenyl, arylalkyl, arylalkenyl, diarylalkyl, or --(CH₂)_(m)--A--(CH₂)_(n) --Q; m is 2 to 4 and n is 0 to 3; A is --O--, or a singlebond; Q is phenyl substituted with R⁷ or naphthyl substituted with R⁷ ;R⁷ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, aryl,aryloxy, or --CO-aryl; R⁴ and R⁵ are each independently hydrogen,methyl, ethyl, n-propyl or n-butyl; and R⁶ is hydrogen or halogen.
 13. Amethod for determining a compound's ability to inhibit the aggregationof amyloid proteins, the method comprising:a. combining solutions of thecompound and amyloid proteins; b. introducing into the solution alabeled compound of Formula I or a pharmaceutically acceptable salt,ester, or amide thereof ##STR28## wherein X and Y are each independentlyC or N and the X═Y double bond has the trans configuration; Z is##STR29## R¹ and R² are each independently hydrogen, C₁ -C₆ alkyl, C₁-C₆ alkoxy, hydroxy, halogen, amino, di(C₁ -C₆ alkyl)amino, mono(C₁ -C₆alkyl)amino, nitro, C₁ -C₆ thioalkoxy, or R¹ and R² combined form abenzene, cyclopentane, or cyclohexane ring that is fused to the phenylring; R³ is a lone pair of electrons, C₁ -C₁₀ alkyl, C₂ -C₁₀ alkenyl,arylalkyl, (heteroaryl)alkyl, (cycloalkyl)alkyl, arylalkenyl,diarylalkyl, or --(CH₂)_(m) --A--(CH₂)_(n) --Q; m is 1 to 6 and n is 0to 6; A is --O--, --S--, --NR⁴ , C═O, or a single bond; Q is phenylsubstituted with R⁷ or naphthyl substituted with R⁷ ; R⁷ is hydrogen, C₁-C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, amino, di(C₁ -C₆alkyl)amino, nitro, C₁ -C₆ thioalkoxy, aryl, heteroaryl, aryloxy,--CO-aryl, or arylthio; R⁴ and R⁵ are each independently hydrogen, C₁-C₆ alkyl or --NR⁴ R⁵ represents a 5-, 6- or 7-membered ring containingnitrogen; and R⁶ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy,halogen, amino, di(C₁ -C₆ alkyl)amino, nitro, or C₁ -C₆ thioalkoxy; c.filtering or centrifuging the solution; and d. determining the amount oflabeled compound in the filtrate or supernatant.
 14. The method of claim13 whereinX═Y is C═C or N═N; R¹ and R² are each independently hydrogen,C₁ -C₆ alkyl, C₁ -C₆ alkoxy, halogen, nitro, C₁ -C₆ thioalkoxy, or R¹and R² combined form a benzene, cyclopentane, or cyclohexane ring thatis fused to the phenyl ring; R³ is C₁ -C₁₀ alkyl, C₂ -C₁₀ alkenyl,arylalkyl, (cycloalkyl)alkyl, arylalkenyl, diarylalkenyl, or --(CH₂)_(m)--A--(CH₂)_(n) --Q; m is 1 to 5 and n is 0 to 4; A is --O--, --S--, or asingle bond; Q is phenyl substituted with R⁷ or naphthyl substitutedwith R⁷ ; R⁷ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen,amino, di(C₁ -C₆ alkyl)amino, nitro, C₁ -C₆ thioalkoxy, aryl, aryloxy,--CO-aryl, or arylthio; R⁴ and R⁵ are each independently hydrogen or C₁-C₆ alkyl; and R⁶ is hydrogen, C₁ -C₆ alkyl, or halogen.
 15. The methodof claim 13 whereinX═Y is C═C or N═N; R¹ and R² are each independentlyhydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, halogen, nitro, or R¹ and R²combined form a (4,5), (5,6), or (6,7) benzene ring fused to the phenylgroup; R³ is C₁ -C₁₀ alkyl, C₂ -C₁₀ alkenyl, arylalkyl, arylalkenyl,diarylalkyl, or --(CH₂)_(m) --A--(CH₂)_(n) --Q; m is 2 to 4 and n is 0to 3; A is --O--, or a single bond; Q is phenyl substituted with R⁷ ornaphthyl substituted with R⁷ ; R⁷ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆alkoxy, hydroxy, halogen, aryl, aryloxy, or --CO-aryl; R⁴ and R⁵ areeach independently hydrogen, methyl, ethyl, n-propyl, or n-butyl; and R⁶is hydrogen or halogen.
 16. A compound of the Formula I or apharmaceutically acceptable salt, ester, or amide thereof ##STR30##wherein X and Y are each independently C or N and the X═Y double bondhas the trans configuration;Z is ##STR31## R¹ and R² are eachindependently hydrogen, C₁ -C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen,amino, di(C₁ -C₆ alkyl)amino, mono(C₁ -C₆ alkyl)amino, nitro, C₁ -C₆thioalkoxy, or R¹ and R² combined form a benzene, cyclopentane, orcyclohexane ring that is fused to the phenyl ring; R³ is a lone pair ofelectrons, C₁ -C₁₀ alkyl, C₂ -C₁₀ alkenyl, arylalkyl, (heteroaryl)alkyl,di(cycloalkyl)alkyl, arylalkenyl, diarylalkyl, or --(CH₂)_(m)--A--(CH₂)_(n) --Q; m is 1 to 6 and n is 0 to 6; A is --O--, --S--,--NR⁴⁻, C═O, or a single bond; Q is phenyl substituted with R⁷ ornaphthyl substituted with R⁷ ; R⁷ is hydrogen, C₁ -C₆ alkyl, C₁ -C₆alkoxy, hydroxy, halogen, amino, di(C₁ -C₆ alkyl)amino, nitro, C₁ -C₆thioalkoxy, aryl, heteroaryl, aryloxy, --CO-aryl, or arylthio; R⁴ and R⁵are each independently hydrogen, C₁ -C₆ alkyl or --NR⁴ R⁵ represents a5-, 6- or 7-membered ring containing nitrogen; and R⁶ is hydrogen, C₁-C₆ alkyl, C₁ -C₆ alkoxy, hydroxy, halogen, amino, di(C₁ -C₆alkyl)amino, nitro, or C₁ -C₆ thioalkoxy, and one or more atoms in thecompound has been replaced with a radioisotope.
 17. The compound ofclaim 16 wherein the radioisotope is ³ H, ¹²³ I, ¹²⁸ I, ¹³¹ I, ³⁵ S, ¹¹C, ¹⁵ O, or ¹⁸ F.